Figure 4. Functional consequences of IKKα ablation on specific CXCL12 migration parameters.

(A): IKKα^f/f:CreERT2 MEFs were incubated with or without 4-OHT (100 nM) for 36 hours, and migration assays were performed using serum free medium (SF), or in response to the same media containing CXCL12 (30 ng/ml) or the positive control PDGF (10 ng/ml). Numbers represent mean ± SEM of cells per high power field (n = 3), ** = p<0.01, * = p <0.05, NS = not significant. (B and C): Cells were exposed CXCL12 gradients (0-30 ng/ml) in μ slides for 1 hour, and their movement was recorded by time-lapse microscopy. Red lines are tracks of cells moving in the direction of the CXCL12 gradient, and black lines are cell tracks moving in other directions. The difference in the number of directional and non-directional tracks between WT and the IKKα ablated MEFs is statistically significant (χ² test **p<0.01); and bar graphs summarizing these results are shown to the right of panel C. (D and E): WT and IKKα KO (4-OHT treated) cell tracks in Panels B & C were analyzed for their relative Euclidean distances and velocities, *p<0.05 and **p<0.01 by two-tailed Student's t tests.